Building Automation: An Intelligently Green Building
Long before BAS became the standard technology for commercial building control and even longer before LEED® became the de facto standard for defining a green building, the concept of an intelligent building was born. Of course, the ingredients of an intelligent building have changed over the years.
Today, the question is how much can the green initiative benefit from intelligent building technology? This issue was recently discussed during the June 25th Engineered System’s webinar titled, “Integration + Green = High Performance.” You can view an archived version of this webinar at http://webinars.esmagazine.com.
Intelligent building technology uses the integration and/or optimization of computerized devices to improve building operation, not only from a resource conservation standpoint, but also for the purpose of improving occupant productivity. (The latter part of this informal definition sounds a lot like that of a green building as defined by the USGBC and LEED.)
The more obvious examples often associated with building intelligence include techniques that rely almost exclusively on optimization of building control strategies (rather than integration with other systems). Nevertheless, these strategies still can contribute greatly to improving a building’s energy efficiency, such as:
- Load-based HVAC control – The dynamic reset of air handler supply temperatures/pressures and central plant supply temperature based on the actual heating/cooling loads in the spaces (VAV box damper position, etc.).
- Demand controlled ventilation – The dynamic reset of outside air below that required by code based on the actual number of building occupants.
- Demand limiting – On/off or reset control of HVAC or other electrical equipment to reduce the impact electrical demand (kW) costs.
By nearly any measure, the above examples improve the greenness of a building. Whether they actually contribute to a building’s LEED certification is another matter (see the webinar information for more on this issue). This depends on the creativity of the A/E team’s approach to meeting the LEED credits.
A different and less obvious example is the use of a structured wiring system shared by both the building low-voltage controls (HVAC controls, lighting, etc.) and the building telephone, data systems, etc. By combining what would have been multiple underutilized wiring systems into one system, haven’t we achieved something that is the epitome of what a green building is supposed to do - conserve resources (in this case, copper)?
The other end of the building intelligence scale includes concepts that involve a high degree of data integration - not only between low-voltage control systems but also with other systems that are outside of the normal realm of building automation. These “other” systems include those for building management (CMMS, BIM, etc.) and the business enterprise (financial, a Microsoft Exchange Server, etc.). Some interesting examples of this higher-level of intelligence include:
- Building automation alarms (or better still FDD - fault diagnostic and detection -software messages) initiating CMMS workorders.
- Demand response through an internet-connected utility meter, whereby changes in building control can automatically occur as energy prices change.
- An occupant-accessible website for controlling an occupants comfort level and/or extending HVAC system operating hours. The latter function might involve automatic XML communications with (or modification of a SQL database for) a financial system, so that costs could be added to the department’s share of the building operating expenses or to a tenant’s lease invoice.